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This work aims to achieve the 6000t compression-shear test machine frame design with the lightweight. The force condition of the compression-shear test machine frame under limited working conditions is first analyzed, and the static analysis of the compression-shear test machine frame is performed using ABAQUS. Then, taking the volume of the frame of the compression-shear testing machine as the constraint condition, the topology optimization of the compression-shear testing machine frame is performed using the variable density method of topology optimization, and the model is reconstructed accordingly. Finally, not only the static characteristics of the frame before and after optimization but also the modal characteristics of the frame before and after optimization and the dynamic characteristics after sudden unloading are compared and analyzed. The results show that the weight of the frame decreases by 14.5% after optimization, and the maximum static stress of the frame is still less than the yield strength of the material; the maximum displacement is still less than the allowable maximum displacement, which meets the requirements of static strength and stiffness. The natural frequency of each mode is much greater than the working frequency, which meets the requirements of dynamic stiffness. After sudden unloading, the maximum dynamic stress of beams, columns, and base of the frame are less than the yield strength of materials, which meets the requirements of dynamic strength.

An electrostatically charged spacecraft is subject to the Lorentz force and torque when moving in the geomagnetic field. By active modulation of the surface charge, the induced Lorentz force and to...

A novel flexible zinc oxide nanorods (NRs)/poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) nanocomposite was prepared by electrospinning for fabricating piezoelectric nanogenerator (PNG). The NRs were used as nanofillers of piezoelectric P(VDF-TrFE), which can enhance the electroactive β-crystal ratio as well as the crystallinity of P(VDF-TrFE). It has been found that the addition of different levels of piezoelectric ZnO NRs can improve the overall performance of PNG made with electrospun membranes. The PNG comprised by 10 wt% ZnO NRs/P(VDF-TrFE) nanocomposite demonstrates an outstanding output open-circuit voltage (61 V) and short-circuit current (2.2 μA). It has been concluded that the ion–dipole interaction between NRs and electroactive β-crystals of P(VDF-TrFE) are useful for the construction of the high-performance flexible PNG. Besides, the output power generated from the PNG can directly light 25 commercial light-emitting diodes, and also capable to charge up a capacitor (4.7 μF) and reached 2.1 V in 2 min, which indicates the potential of the PNG for flexible wearable electronic devices.

Spectral clustering makes use of the spectrum of an input affinity matrix to segment data into disjoint clusters. The performance of spectral clustering depends heavily on the quality of the affinity matrix. Commonly used affinity matrices are constructed by either the Gaussian kernel or the self-expressive model with sparse or low-rank constraints. A technique called diffusion which acts as a post-process has recently shown to improve the quality of the affinity matrix significantly, by taking advantage of the contextual information. In this paper, we propose a variant of the diffusion process, named Self-Supervised Diffusion, which incorporates clustering result as feedback to provide supervisory signals for the diffusion process. The proposed method contains two stages, namely affinity learning with diffusion and spectral clustering. It works in an iterative fashion, where in each iteration the clustering result is utilized to calculate a pseudo-label similarity so that it can aid the affinity learning stage in the next iteration. Extensive experiments on both synthetic and real-world data have demonstrated that the proposed method can learn accurate and robust affinity, and thus achieves superior clustering performance.

With the popularization of the 5G (fifth generation), cloud computing and Internet of Things, China has developed an multi-dimensional and all-round smart tourism system, which has become China's development trend in tourism industry. Based on the background of post-pandemic of COVID-19, this paper analyzed the present research and application status of tourism. This paper analyzed the research status in the field of AR in tourism based on AR (Artificial Intelligence) technology. It studied the future how AR visualization technology could be applied in China's smart tourism development and how would the tourists be endowed with various feelings with the use of the technology

Background Gastrointestinal mucormycosis (GIM) is a rare, opportunistic fungal infection with poor prognosis. Clinically, it is difficult to diagnose GIM owing to its nonspecific clinical symptoms and poor suspicion. The estimated incidence of GIM is inaccurate, and most cases are diagnosed accidentally during surgery or upon postmortem examination. GIM usually occurs in patients with immune deficiencies or diabetes. Here, we report two cases of immunocompetent young patients with GIM who had good prognosis after treatment. Compared to other case reports on GIM, our cases had unusual infection sites and no obvious predisposing factors, which make it important to highlight these cases. Case presentation The first case was that of a 16-year-old immunocompetent boy who was admitted with gastrointestinal bleeding and perforation due to a gastric ulcer. Strategies used to arrest bleeding during emergency gastroscopy were unsuccessful. An adhesive mass was then discovered through laparoscopy. The patient underwent type II gastric resection. Pathological examination of the mass revealed bacterial infection and GIM. The second case was of a 33-year-old immunocompetent woman with a recent history of a lower leg sprain. The patient subsequently became critically ill and required ventilatory support. After hemodynamic stabilization and extubation, she presented with hematemesis due to exfoliation and necrosis of the stomach wall. The patient underwent total gastrectomy plus jejunostomy. The pathology results revealed severe bacterial infection and fungal infection that was confirmed as GIM. The patient fully recovered after receiving anti-infective and antifungal treatments. Conclusions Neither patient was immunosuppressed, and both patients presented with gastrointestinal bleeding. GIM was confirmed via pathological examination. GIM is not limited to immunocompromised patients, and its diagnosis mainly relies on pathological examination. Early diagnosis, timely surgical treatment, and early administration of systemic drug treatment are fundamental to improving its prognosis.

Optical gyroscopes play important roles in the field of angular velocity measurement. Improving the accuracy of the Sagnac effect is always an attractive research topic. In this work, a new scheme is proposed and demonstrated by using a polarization-maintaining bidirectional coupled optoelectronic oscillator (COEO) incorporating a Sagnac loop structure. In COEO resonant cavity, optical carrier and one of the first-order sidebands are separated by polarization delay interferometers, and propagate in opposite directions in the Sagnac loop. The rotation-induced phase difference between optical carrier and first-order sideband produces a frequency shift in COEO system. Moreover, for bidirectional system, the trends of resonant frequencies shift are opposite. Therefore, the difference of bidirectional resonant frequencies is the summation of unidirectional rotation-induced frequency shift. And less-complex, high-resolution microwave detection technology is used to improve the detection resolution of frequency difference. Therefore, a high-sensitivity angular velocity measurement system is implemented, with a sensitivity scale of 172.04 kHz/(rad/s). Theoretically, a minimally detectable angular velocity is 1.2 °/h.

Tumor mutation burden (TMB) was a promising marker for immunotherapy. We aimed to investigate the prognostic role of TMB and its relationship with immune cells infiltration in gastric cancer (GC). We analyzed the mutation landscape of all GC cases and TMB of each GC patient was calculated and patients were divided into TMB-high and TMB-low group. Differentially expressed genes (DEGs) between the two groups were identified and pathway analysis was performed. The immune cells infiltration in each GC patient was evaluated and Kaplan–Meier analysis was performed to investigate the prognostic role of immune cells infiltration. At last, hub immune genes were identified and a TMB prognostic risk score (TMBPRS) was constructed to predict the survival outcome of GC patients. The relationships between mutants of hub immune genes and immune infiltration level in GC was investigated. We found higher TMB was correlated with better survival outcome and female patients, patients with T1-2 and N0 had higher TMB score. Altogether 816 DEGs were harvested and pathway analysis demonstrated that patients in TMB-high group were associated with neuroactive ligand–receptor interaction, cAMP signaling pathway, calcium signaling pathway. The infiltration of activated CD4+ memory T cells, follicular helper T cells, resting NK cells, M0 and M1 macrophages and neutrophils in TMB-high group were higher compared than that in TMB-low group and high macrophage infiltration was correlated with inferior survival outcome of GC patients. Lastly, the TMBPRS was constructed and GC patients with high TMBPRS had poor prognosis.

Background. Perioperative topical tranexamic acid as antifibrinolytic agent is often used for total joint replacement to reduce bleeding currently. Staphylococcus aureus was the most common isolates from perioperative infection of prosthetic joint. The influence of topical application with tranexamic acid on the incidence of acute prosthetic joint infection of Staphylococcus aureus has not been clarified. Methods. Mouse model of Staphylococcus aureus knee prosthesis infection was constructed. Tranexamic acid was intra-articular injected during the perioperative period. CFU counting from tissue and implant sample was evaluated 3 days and 7 days after inoculating of Staphylococcus aureus. Bacterial growth curve, biofilm formation, aggregation, and plasmin inhibition of Staphylococcus aureus were tested with tranexamic acid added to the synovial culture medium. Results. There were no significant differences of CFU counting from tissue and implant samples in knee prosthesis infection after a single local injection of tranexamic acid at the postoperative 3 or 7 days. The amount of bacterial colonization on the surface of implant increased after 3 days’ continuous local injection of tranexamic acid. Tranexamic acid has no effect on bacterial growth at the concentration (10 mg/ml) of clinical application, but it can inhibit bacterial aggregation and mildly inhibit biofilm formation. Plasmin can significantly inhibit biofilm formation which can be revised by adding tranexamic acid. Conclusion. Although continuous local injection of tranexamic acid can promote the biofilm formation of Staphylococcus aureus on the surface of articular implant, it has clinical safety for using one single local injection of tranexamic acid during the perioperative period.

We propose a novel two-user non-orthogonal multiple access (NOMA) visible light communication (VLC) system. The spectral efficiencies of the two users can be increased by using spatial modulation (SM) and constellation rotation.

Amyotrophic lateral sclerosis (ALS) is a fatal neuromuscular disease characterized by motor neuron (MN) death. Lipid dysregulation manifests during disease; however, it is unclear whether lipid homeostasis is adversely affected in the in the spinal cord gray matter (GM), and if so, whether it is because of an aberrant increase in lipid synthesis. Moreover, it is unknown whether lipid dysregulation contributes to MN death. Here, we show that cholesterol ester (CE) and triacylglycerol levels are elevated several-fold in the spinal cord GM of male sporadic ALS patients. Interestingly, HMG-CoA reductase, the rate-limiting enzyme in cholesterol synthesis, was reduced in the spinal cord GM of ALS patients. Increased cytosolic phospholipase A2 activity and lyso-phosphatidylcholine (Lyso-PC) levels in ALS patients suggest that CE accumulation was driven by acyl group transfer from PC to cholesterol. Notably, Lyso-PC, a byproduct of CE synthesis, was toxic to human MNsin vitro. Elevations in CE, triacylglycerol, and Lyso-PC were also found in the spinal cord of SOD1G93Amice, a model of ALS. Similar to ALS patients, a compensatory downregulation of cholesterol synthesis occurred in the spinal cord of SOD1G93Amice; levels of sterol regulatory element binding protein 2, a transcriptional regulator of cholesterol synthesis, progressively declined. Remarkably, overexpressing sterol regulatory element binding protein 2 in the spinal cord of normal mice to model CE accumulation led to ALS-like lipid pathology, MN death, astrogliosis, paralysis, and reduced survival. Thus, spinal cord lipid dysregulation in ALS likely contributes to neurodegeneration and developing therapies to restore lipid homeostasis may lead to a treatment for ALS.SIGNIFICANCE STATEMENTNeurons that control muscular function progressively degenerate in patients with amyotrophic lateral sclerosis (ALS). Lipid dysregulation is a feature of ALS; however, it is unclear whether disrupted lipid homeostasis (i.e., lipid cacostasis) occurs proximal to degenerating neurons in the spinal cord, what causes it, and whether it contributes to neurodegeneration. Here we show that lipid cacostasis occurs in the spinal cord gray matter of ALS patients. Lipid accumulation was not associated with an aberrant increase in synthesis or reduced hydrolysis, as enzymatic and transcriptional regulators of lipid synthesis were downregulated during disease. Last, we demonstrated that genetic induction of lipid cacostasis in the CNS of normal mice was associated with ALS-like lipid pathology, astrogliosis, neurodegeneration, and clinical features of ALS.

In recent years, bariatric surgery has emerged as a promising treatment for type 2 diabetes. Bariatric surgery is known to cause alterations in the relative abundance and composition of gut microbiota, which may lead to alterations in the levels of Short-Chain Fatty Acids (SCFAs) that are produced during fermentation by gut microbes. However, little is known about the mechanism of improved glucose metabolism mediated by gut microbiota following bariatric surgery. The aim of our study was to explore whether changes in gut microbiota and in fecal SCFA could be detected following single-anastomosis duodenal jejunal bypass (DJB-sa) surgery, a type of bariatric surgery, and whether these alterations might be related to the improvement of glucose metabolism. To this end, we performed DJB-sa or SHAM surgery on Goto-Kakisaki (GK) rats. We then compared the glucose metabolism as well as changes in gut microbiota and SCFAs levels between both groups. Our results showed that DJB-sa surgery was associated with a significant decrease in fasting blood glucose (FBG), intraperitoneal glucose tolerance test (IPGTT), and fasting serum insulin (FSI). And, DJB-sa led to a change in the composition of gut microbiota including an increase in the relative abundance of SCFA-producing bacteria (Bifidobacterium and Subdoligranulum). Moreover, the levels of six SCFAs in feces, as well as the intestinal expression of SCFA receptors including G-protein-coupled receptor 41 (GPR41), G-protein-coupled receptor 43 (GPR43), and G-protein-coupled receptor 109A (GPR109A), and the expression of Glucagon-like peptide-1 (GLP-1) displayed a significant increase following DJB-sa compared with the Sham group. Thus, the gut microbiota may contribute to the improvement of glucose metabolism in type 2 diabetes following DJB-sa. In conclusion, our study shows that DJB-sa improves glucose metabolism by modulating gut microbiota and by increasing short-chain fatty acid production.

A novel photonic scheme of microwave waveforms generator based on a dual-loop optoelectronic oscillator (OEO) is experimentally verified. A 10-GHz microwave signal generated by OEO is modulated onto the directly modulated laser (DML) and the phase modulator (PM) simultaneously. By adjusting the driven power of the DML and the PM and the phase difference between the pulse signal inputted into the PM and the PM’s driven signal, the desired optical spectrum is obtained. By passing appropriate dispersion, the optical spectrum can be converted into desired waveform. In this experiment, a series of waveforms with the shapes of sawtooth/reversed-sawtooth, triangle, and pulse are generated.

A self-starting multiple microwave waveform signal generator based on a dual-loop optoelectronic oscillator (OEO) is proposed. The structure of the dual-loop OEO with two wavelengths can suppress the random beating noise effectively and generate the microwave signal with low phase noise (−119.8 dBc/Hz at 10 kHz). Then square waveform is generated by setting the modulation index to be 1.15. Sawtooth (Reversed-sawtooth) waveform is obtained by combining a square and a frequency doubling sinusoidal signal which is got by setting the bias of the other MZM driven by OEO at the null point (maximum point). The triangular waveform is obtained by combining two oscillation signal envelopes with a relative 1/4 period time delay, when the modulation index of the MZM is set to 0.7555. The operation principle is theoretically analyzed and simulated. In experimental demonstration, full-duty-cycle and high quality square, sawtooth (reversed-sawtooth) and triangular waveform signals with low phase noise at 4.9641-GHz are achieved. An external synthesizer is replaced by the high-quality microwave signal in this structure.

Purpose Studies have found that long noncoding RNA HEIH (lncRNA-HEIH) is upregulated and facilitates hepatocellular carcinoma tumor growth. However, its clinical significances, roles, and action mechanism in colorectal cancer (CRC) remains unidentified. Materials and methods lncRNA-HEIH expression in CRC tissues and cell lines was measured by quantitative real-time polymerase chain reaction. Cell CountingKit-8, ethynyl deoxyuridine incorporation assay, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, and nude mice xenografts assays were performed to investigate the roles of lncRNA-HEIH. RNA pull-down, RNA immunoprecipitation, chromatin immunoprecipitation, and luciferase reporter assays were performed to investigate the action mechanisms of lncRNA-HEIH. Results In this study, we found that lncRNA-HEIH is significantly increased in CRC tissues and cell lines. lncRNA-HEIH expression is positively associated with tumor size, invasion depth, and poor prognosis of CRC patients. Enhanced expression of lncRNA-HEIH promotes CRC cell proliferation and decreases apoptosis in vitro, and promotes CRC tumor growth in vivo. Whereas knockdown of lncRNA-HEIH inhibits CRC cell proliferation and induces apoptosis in vitro, and suppresses CRC tumor growth in vivo. Mechanistically, lncRNA-HEIH physically binds to miR-939. The interaction between lncRNA-HEIH and miR-939 damages the binding between miR-939 and nuclear factor κB (NF-κB), increases the binding of NF-κB to Bcl-xL promoter, and promotes the transcription and expression of Bcl-xL. Moreover, Bcl-xL expression is positively associatedwith lncRNA-HEIH in CRC tissues. Blocking the interaction between lncRNA-HEIH and miR-939 abolishes the effects of lncRNA-HEIH on CRC tumorigenesis. Conclusion This study demonstrated that lncRNA-HEIH promotes CRC tumorigenesis through counteracting miR-939‒mediated transcriptional repression of Bcl-xL, and suggested that lncRNA-HEIH may serve as a prognostic biomarker and therapeutic target for CRC.

Background Colorectal cancer (CRC) has a high worldwide incidence and mortality. Tumor metastasis is one of the primary reasons for the poor prognosis of CRC patients. However, the mechanism underlying CRC metastasis is still unclear. Myosin 1B (MYO1B) is important for cell migration and motility and is part of the myosin superfamily that contains various myosins. Studies of prostate, cervical, and head and neck cancer have revealed preliminary findings concerning the effect of MYO1B on tumor metastasis. However, the role of MYO1B in CRC metastasis, as well as its underlying mechanism, remains unknown. Methods Quantitative real-time PCR and immunohistochemical staining methods were used to analyze the expression of MYO1B in human CRC and normal mucosa tissues. Lentivirus vector-based MYO1B oligonucleotides and short hairpin RNA (shRNA) were used to examine the functional relevance of MYO1B in CRC cells. Co-immunoprecipitation, western blotting, and immunofluorescence assays were used to investigate the underlying mechanism of MYO1B-mediated cell migration. Results The expression of MYO1B was increased in most CRC tissues and was positively associated with a greater risk of tumor metastasis and poor prognosis for patients. MYO1B was significantly associated with the migration and invasion properties of CRC cells in vitro and in vivo. MYO1B promoted F-actin rearrangement through the ROCK2/LIMK/Cofilin axis by enhancing the activation of RhoA. MYO1B also promoted the assembly of focal adhesions by targeting RhoA. Conclusions MYO1B plays a vital role in CRC metastasis by promoting the activation of RhoA. MYO1B may not only be a valid biomarker for predicting the risk of metastasis and poor prognosis in CRC but may also be a potential therapeutic target for patients with a high risk of tumor metastasis.

A photonic multi-channel terahertz (THz) wireless transmission system in the 350-475 GHz band is experimentally demonstrated. The employment of six THz carriers modulated with 10 Gbaud Nyquist quadrature phase-shift keying baseband signal per carrier results in an overall capacity of up to 120 Gb/s. The THz carriers with high-frequency stability and low phase noise are generated based on photonic photomixing of 25-GHz spaced six optical tones and a single optical local oscillator derived from a same optical frequency comb in an ultrabroadband uni-travelling carrier photodiode. The bit-error-rate performance below the hard decision forward error correction threshold of 3.8×10 -3 for all the channels is successfully achieved after wireless delivery. Furthermore, we also investigate the influence of the harmonic spurs in a THz receiver on the performance of transmission system, and the experimental results suggest more than 30 dB spur suppression ratio in downconverted intermediate frequency signals for obtaining less than 1 dB interference.

In order to enable the calibration model to be effectively transferred among multiple instruments and correct the differences between the spectra measured by different instruments, a new feature transfer model based on partial least squares regression (PLS) subspace (PLSCT) is proposed in this paper. Firstly, the PLS model of the master instrument is built, meanwhile a PLS subspace is constructed by the feature vectors. Then the master spectra and the slave spectra are projected into the PLS subspace, and the features of the spectra are also extracted at the same time. In the subspace, the pseudo predicted feature of the slave spectra is transferred by the ordinary least squares method so that it matches the predicted feature of the master spectra. Finally, a feature transfer relationship model is constructed through the feature transfer of the PLS subspace. This PLS-based subspace transfer provides an efficient method for performing calibration transfer with only a small number of standard samples. The performance of the PLSCT was compared and assessed with slope and bias correction (SBC), piecewise direct standardization (PDS), calibration transfer method based on canonical correlation analysis (CCACT), generalized least squares (GLSW), multiplicative signal correction (MSC) methods in three real datasets, statistically tested by the Wilcoxon signed rank test. The obtained experimental results indicate that PLSCT method based on the PLS subspace is more stable and can acquire more accurate prediction results.

A new photonic approach for triangular waveform generation by making full use of the polarization sensitive characteristic of the single-drive Mach–Zehnder modulator (MZM) is proposed and experimentally demonstrated. In this method, the MZM is biased at minimum transmission point and its best modulation axis has an angle with the polarization direction of injection continuous wave (CW). Due to the polarization dependent modulation efficiency of a MZM, the odd-order modulation sidebands can be generated on the parallel polarization component but only the optical carrier is presented on the orthogonal direction. After a polarizer, the required Fourier components can be projected on the same polarization direction, which contribute a triangular pulse stream by photodetection. In the experimental demonstration, triangular waveforms with repetition frequencies of 8, 10, and 12 GHz are successfully generated, respectively.

We propose a concept of wavelength synchronization to ensure the stability of ultra-dense channels in an ultra-dense wavelength division multiplexing passive optical network (UDWDM-PON) transmitter. A mode-locked laser is used to provide wavelength references for users. By injection locking the semiconductor laser, the separation of the wavelength reference is realized in an optical line terminal. The downlink and uplink wavelength references are interlaced and distributed to facilitate the synchronization of uplink carriers. In the optical network unit, the uplink optical carriers are filtered by injection locking semiconductor lasers, which achieve wavelength synchronization for the uplink users. In this Letter, an adaptive wavelength synchronization transmitter for UDWDM-PON is realized with a channel spacing of 5 GHz.

This article presents the research on the ablation threshold of fused silica glass processed by femtosecond laser in different environments, such as air, distilled water, and pure alcohol solution. At present, studies on ultra-short pulse lasers on materials mainly focus on the ablation threshold and material removal mechanism of specific materials. By analyzing the ablation threshold of the material, the laser processing efficiency can be greatly improved. Therefore, this paper mainly studied the material removal mechanism of fused silica and calculated the ablation threshold of fused silica in different environments. By analyzing the experimental results, we found that the surface-ablation threshold of fused silica glass can be relatively reduced in liquid environment relative to the air environment. Compared with distilled water, the surface-ablation threshold in pure alcohol solution can be significantly decreased. Besides, by comparing the results, the surface morphology quality in the liquid solutions is superior to the air. The research content of this article has given a certain theoretical guidance for the processing of transparent materials and laid a certain foundation for subsequent research work.

In this paper, a terahertz (THz) wireless communication system at 400 GHz with various modulation formats [on-off keying (OOK), quadrature phase-shift keying (QPSK), 16-quadrature amplitude modulation (16-QAM), and 32-quadrature amplitude modulation (32-QAM)] is experimentally demonstrated based on photonic generation of highly pure THz carriers. The experimental THz wireless photonic transmission system is enabled by the ultrawideband behavior of an antenna-integrated unitraveling-carrier-photodiode-based transmitter and a Schottky mixer-based THz receiver. In the experiment, a phase-correlated optical frequency comb (OFC) is created for photomixing generation of the desired THz carrier frequencies with low phase noise. The OFC allows for the generation of flexibly tunable THz carrier frequencies. The performance of the generated THz carriers is experimentally characterized in terms of phase noise, spectrum purity, tunability, and long-term stability. In the case of generating 400 GHz carrier, the measured timing jitter, linewidth, and long-term stability in the experiment are 51.5 fs, less than 2 Hz, and less than ±1 Hz with 3 hours, respectively. We also theoretically analyze the phase noise of photonically generated THz beat-notes when phase correlation of two optical comb tones is damaged due to their path-length difference. In addition, we demonstrate THz wireless transmission of various modulation formats, including OOK, QPSK, 16-QAM, and 32-QAM at beyond 10 Gb/s in such a system, and the measured bit error rate (BER) performance for all the signals after 0.5 m free-space delivery is below the hard decision forward error correction threshold of 3.8 × 10-3. Furthermore, the influence of THz carrier purity on the system performance is experimentally analyzed with respect to the BER of the THz communication signals.

A novel scheme of a highly stable dual-wavelength short optical pulse source (SOPS) based on a dual-loop optoelectronic oscillator (OEO) with two wavelengths is demonstrated. The structure of the dual-loop OEO with two wavelengths can suppress the random beating noise effectively and generate the microwave signal with low phase noise ( $-$ 122.4 dBc/Hz at 10 kHz) . It consists of two directly modulated lasers and a phase modulator (PM) . The light that is directly modulated by the large signal generated from the OEO is injected into the PM to achieve remarkable chirp. Then, by optimizing the length of the dispersion compensating fiber, the optical pulses are further compressed. In the experiment, the SOPS with dual wavelengths is generated simultaneously. The repetition rate, pulse width, and timing jitter of the SOPS are 10 GHz, 2.9 ps, and 12.5 fs, respectively. In particular, the loop drift of the OEO is effectively compensated by fiber stretchers using phase-locked-loop technology. The frequency drift of the microwave signal is less than $\pm$ 73.3 mHz for a long-term measurement with a duration of 1 h. Therefore, the long-term stability of SOPS is guaranteed.

A Lorentz spacecraft is an electrostatically charged space vehicle that could modulate the surface charge to induce Lorentz force as propellantless electromagnetic propulsion for orbital maneuvering. Modeling the Earth's magnetic field as a tilted dipole corotating with Earth, a dynamical model of Lorentz-augmented spacecraft relative motion about arbitrary elliptic orbits is developed, based on which the optimal open-loop trajectory of Lorentz-augmented rendezvous is solved by Gauss pseudospectral method. To track the open-loop trajectory in the presence of external perturbations and without velocity measurements, a reduced-order observer and an output feedback controller are designed, ensuring the stability of the closed-loop system by a Lyapunov-based approach. Numerical simulations verify the validity of both the open-loop and closed-loop controllers.

A novel stable multiwavelength single longitudinal mode (SLM) dual ring Brillouin fiber laser is proposed and demonstrated. Dual ring configuration with 100 and 10 m length of single mode fiber guarantees each Stokes and anti-Stokes waves in SLM status. Linewidth of the first Stokes wave is below 4 kHz with 60 dB sidemode suppression value. 7 stable SLM lasing wavelengths including the pump with a 5 dB bandwidth of 0.5, 0.084 nm wavelength spacing and 15 dB average optical signal-to-noise ratio are generated through the cascaded SBS and degenerate FWM process. The laser can freely be tuned 30 nm range from 1535 to 1565 nm. The power fluctuation of the first Stokes wave is about 8 % measured by Data Acquisition System in 1 h.

Using a directly modulated laser to injection locking the high-order sideband of modulated light, multiplication frequency is detected at its radio frequency port. Instead of employing photodetector, the proposed tunable frequency multiplication system costs low obviously.

We propose a long-range, high-precision distance measurement system with low complexity and cost based on optoelectronic oscillator. The relative measurement accuracy of 1.667 km is $3\times 10^{-9}$ .

A 10 GHz frequency transfer experiment was realized over a 35 km fiber link. An injection-locked optoelectronic oscillator was used in the remote site for stabilization of the phase noise.

Period-doubling bifurcation, period-trebling bifurcation and period-quadrupling bifurcation of the pulse train in an actively Q-switched fiber laser is experimentally observed in this paper.

To accommodate the demand of exponentially increased global wireless data traffic, the prospective data rates for wireless communication in the market place will soon reach 100 Gb/s and beyond. In the lab environment, wireless transmission throughput has been elevated to the level of over 100 Gb/s attributed to the development of photonic-assisted millimeter wave and terahertz (THz) technologies. However, most of recent demonstrations with over 100 Gb/s data rates are based on spatial or frequency division multiplexing techniques, resulting in increased system's complexity and energy consumption. Here, we experimentally demonstrate a single channel 0.4 THz photonic-wireless link achieving a net data rate of beyond 100 Gb/s by using a single pair of THz emitter and receiver, without employing any spatial/frequency division multiplexing techniques. The high throughput up to 106 Gb/s within a single THz channel is enabled by combining spectrally efficient modulation format, ultrabroadband THz transceiver and advanced digital signal processing routine. Besides that, our demonstration from system-wide implementation viewpoint also features high transmission stability, and hence shows its great potential to not only decrease the system's complexity, but also meet the requirements of prospective data rates for bandwidth-hungry short-range wireless applications.

A novel dual-loop optoelectronic oscillator (OEO) with different wavelengths is demonstrated. The principle of OEO is analyzed theoretically. There is almost no beating noise due to the optical domain dual-loop with different wavelengths. In our experiment, a 20-GHz radio frequency (RF) with high quality is obtained. The phase noise of the microwave signal is measured to be -120.6 dBc/Hz at 10 kHz. The loop drift of the OEO is compensated by a fiber stretcher using phase-loop locked technology and the stability of the RF has been improved greatly. The frequency drift of the OEO system is

In this paper, modulation formats of M-ary pulse amplitude modulation (PAM)- and M-ary quadrature amplitude modulation (QAM)-asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) could be recognized autonomously in visible light communication (VLC) systems, by using higher order statistics (HOS). Fourth-order cumulants are applied as the decision criterion and the HOS method's correct decision probability is investigated by Monte-Carlo (MC) simulation.

Previous studies used to enumerate circulating tumor cells to predict prognosis and therapeutic effect of colorectal cancer. However, increasing studies have shown that only circulating tumor cells enumeration was not enough to reflect the heterogeneous condition of tumor. In this study, we classified different metastatic-potential circulating tumor cells from colorectal cancer patients and measured FAM172A expression in circulating tumor cells to improve accuracy of clinical diagnosis and treatment of colorectal cancer. Blood samples were collected from 45 primary colorectal cancer patients. Circulating tumor cells were enriched by blood filtration using isolation by size of epithelial tumor cells, and in situ hybridization with RNA method was used to identify and discriminate subgroups of circulating tumor cells. Afterwards, FAM172A expression in individual circulating tumor cells was measured. Three circulating tumor cell subgroups (epithelial/biophenotypic/mesenchymal circulating tumor cells) were identified using epithelial-mesenchymal transition markers. In our research, mesenchymal circulating tumor cells significantly increased along with tumor progression, development of distant metastasis, and vascular invasion. Furthermore, FAM172A expression rate in mesenchymal circulating tumor cells was significantly higher than that in epithelial circulating tumor cells, which suggested that FAM172A may correlate with malignant degree of tumor. This hypothesis was further verified by FAM172A expression in mesenchymal circulating tumor cells, which was strictly related to tumor aggressiveness factors. Mesenchymal circulating tumor cells and FAM172A detection may predict highrisk stage II colorectal cancer. Our research proved that circulating tumor cells were feasible surrogate samples to detect gene expression and could serve as a predictive biomarker for tumor evaluation.

We propose an absolute distance measurement method using alternately oscillating optoelectronic oscillators (OEOs) with high speed, high precision, and long range, and describe the dynamic characteristics of the measurement system. Measurement and reference OEOs are oscillated using a 2×2 optical switch, and rough and fine measurements are achieved by low- and high-order-mode oscillation. The distance is determined by the loop length difference between the two OEOs. OEO length control is not necessary, so the system is simple and the time per measurement is only 40 ms. The maximum measurement error is 3.4 µm with an emulated distance of 7.5 km, and the relative measurement accuracy reaches 4.5×10−10.

Enhanced recovery after surgery (ERAS), initially known as “fast track surgery” (FTS) or “enhanced recovery protocol” (ERP), was originally pioneered in Denmark by Professor Henrik Kehlet, a professor from the University of Copenhagen. Today, this approach has been widely applied in surgery, anesthesia, nursing, and many other professional fields, achieving remarkable results.

A novel single longitudinal mode (SLM) Brillouin fiber laser (BFL) with cascaded ring (CR) Fabry-Perot resonator is proposed and demonstrated. By optimizing the CR length of the single mode fiber cavity at 100 m (or 50 m) and 10 m, stable SLM operation is obtained. Therefore, the threshold power is lower and linewidth is narrower than that of previously reported BFL with 10 m (or 20 m) single cavity. Additionally, there is no additional attenuation except intrinsic loss of optical devices. The measured linewidth with 60 dB (or 45 dB) improved value of side mode suppression ratio is 0.41 kHz (or 3.23 kHz), which is three (or two) orders of magnitude than that of the pump. Using a stabilizing feedback loop based on autotracking technique with polarization maintaining fiber-based optical delay line, the SLM BFL exhibits good performance with 6% power fluctuation in 1 h.

We propose a scheme to incorporate VLC into VLP using OFDMA. The VLP accuracy is improved by measuring the average RSS on subcarrier block. The feasibility of simultaneous VLC has been investigated.

Background Endoscopic axillary lymphadenectomy (EALND) was introduced to clinical work to reduce side effects of conventional axillary lymphadenectomy, while the lipolysis and liposuction of EALND made the process consume more time. The aim of the study was to determine whether immediate liposuction after tumescent solution injection to the axilla could shorten the total time of EALND. Methods Fifty-nine patients were enrolled in the study, 30 of them received EALND with traditional liposuction method (TLM), and the rest 29 patients received EALND with immediate liposuction method (ILM). The operation time, cosmetic result, drainage amount, and hospitalization time of the two groups were compared. Results The median EALND operation time of TLM group and ILM group were 68 and 46 min, respectively, the difference was significant (P 0.05). Conclusions Our work suggests immediate liposuction could shorten the endoscopic axillary lymphadenectomy process, and this method would not compromise the operation results. However, due to the limitations of the research, more work needs to be done to prove the availability and feasibility of immediate liposuction.

By injection locking the first sideband of modulated light, the optical spectrum is broadened because of four-wave mixing (FWM) effect. As a result, continuous optical pulse with same frequency of modulating microwave is generated.

All-optical 1×4 broadcast and 1×3 multicast experiments of a 40-Gb/s return-to-zero on-off keying (RZ-OOK) signal based on a periodically poled lithium niobate (PPLN) waveguide are demonstrated in this letter. Clear opened eye diagrams and error-free performance are achieved for the broadcast signals at 1541.3, 1543.7, 1548.5, and 1550.9 nm. Multicast technology uses cascaded second-harmonic generation and difference-frequency generation in a Ti:PPLN waveguide. An error-free operation with a negligible power penalty is achieved for the three wavelength-division multiplexing multicast signals at 1533, 1537, and 1541 nm.

We propose and experimentally demonstrate THz photonic wireless communication systems with 16-QAM modulation in the 375-450 GHz band. The overall throughput reaches as high as 80 Gbit/s by exploiting four THz channels with 5 Gbaud 16-QAM baseband modulation per channel. We create a coherent optical frequency comb (OFC) for photonic generation of multiple THz carriers based on photo-mixing in a uni-travelling carrier photodiode (UTC-PD). The OFC configuration also allows us to generate reconfigurable THz carriers with low phase noise. The multiple-channel THz radiation is received by using a Schottky mixer based electrical receiver after 0.5 m free-space wireless propagation. 2-channel (40 Gbit/s) and 4-channel (80 Gbit/s) THz photonic wireless links with 16-QAM modulation are reported in this paper, and the bit error rate (BER) performance for all channels in both cases is below the hard decision forward error correction (HD-FEC) threshold of 3.8e-3 with 7% overhead. In addition, we also successfully demonstrate hybrid photonic wireless transmission of 40 Gbit/s 16-QAM signal at carrier frequencies of 400 GHz and 425 GHz over 30 km standard single mode fiber (SSMF) between the optical baseband signal transmitter and the THz wireless transmitter with negligible induced power penalty.

We experimentally analyze the performance of Schottky mixer-based THz receiver in a high-speed THz wireless transmission system incorporating an ultra-broadband uni-travelling carrier photodiode (UTC-PD) as photo-mixing emitter. The multi-channel photonic THz wireless system operates in the 375–450 GHz band with 4×10 GBaud/s QPSK modulation, reaching an overall capacity of 80 Gbit/s. The bit error rate (BER) performance for all the channels reaches below the forward error correction (FEC) threshold of 3.8∗10−3, and the experimental results indicate that the existence of harmonics spurs in the receiver however severely affects the receiver bandwidth and induces the performance degradation of THz wireless communication systems.

We experimentally demonstrate simultaneous 3R regeneration of 4 $\times$ 40-Gbit/s WDM channels, which is based on the four-wave mixing (FWM) in a single dispersion-shifted fiber. The multichannel 3R regeneration performance is validated by bit-error rate (BER) measurements. Receiver powers at a BER of $10^{-9}$ are improved by 5.2 dB, 4.8 dB, 3.3 dB, and 3.9 dB for the four WDM channels, respectively. Mitigation of the interchannel nonlinearities is achieved mainly through an interchannel 0.5-bit slot time delay, which is introduced by differential group delay. Bidirectional propagation and polarization multiplexing are also applied to relieve the interchannel FWM.

Tunable all-optical wavelength conversion (AOWC) of a 40-Gb/s RZ-OOK data signal based on cascaded second-harmonic generation (SHG) and difference-frequency generation (DFG) in a Ti:PPLN waveguide is demonstrated. Error-free performances with negligible power penalty are achieved for the wavelength-converted signal at 1535, 1538, 1541, 1551, 1554, and 1557 nm, respectively.

A novel distributed optical fiber vibration sensing system based on polarization detection is proposed and demonstrated. A Faraday rotator mirror is employed at the end of the system, which eliminates the slow polarization variation of signal light and only responses to rapid polarization change caused by external vibration interference. Based on the sensing signal characteristics, the location of polarization disturbance point can be detected accurately. Experiments on polarization controller simulation and actual vibration detection show that a higher localization accuracy better than 1% is successfully obtained in 13.8 km, 21.2 km and 35.8 km sensing fibers systems.

Artificial sphincters have been developed for patients with fecal incontinence, but finding a way to make such sphincters more "intelligent" remains a problem. We assessed the function of a novel intelligent artificial anal sphincter (IAAS) in vitro and in vivo in rabbits. After the prosthesis was activated, rabbits were continent of feces during 81.4% of the activation time. The fecal detection unit provided 100% correct signals on stool in vitro and 65.7% in vivo. The results indicated that the IAAS could efficiently maintain continence and detect stool; however, the IAAS is still in the preliminary experimental stage and more work is needed to improve the system.

Non-orthogonal multiple access (NOMA) can increase the overall spectral efficiency of visible light communication (VLC) system. In this paper, we proposed a novel scheme to improve the bit error rate (BER) performance of a two-user NOMA VLC system by adjusting superposition constellation. The corresponding closed-form BER expressions are derived. Convex optimization is used to find the optimal parameters of the adjusted superposition constellation, where the overall BER is minimized. The BER performances are evaluated by theoretical analysis, Monte-Carlo (MC) simulation and experiment. The results illustrate that 8.9-dB and 8.1-dB signal-to-noise ratios (SNRs) are reduced to achieve BER of 10−3 for the two users, whose power allocation coefficients are 0.6 and 0.4, respectively.

Based on InAlGaAs multi-quantum wells epitaxy structure for Fabry-Pero laser diode, a multi-quantum wells semiconductor ring laser is realized using ICP dry etching process and polyimide planarization process. The laser is generated in a semiconductor resonator ring and is output by two coupled integrated bus waveguides. The ring diameter is 700 µm and the width of the waveguide is 3 µm. The output optical power-current (P-I) characteristic and the wavelength spectra of the ring laser are measured using a fiber coupled to the cleaved facet of the bus waveguide. The threshold current of the device is 120 mA and the wavelength is 1602 nm at an injected current of 160 mA. In addition, the operation mode for the laser in the resonator ring is roughly discussed based on the P-I characteristic plot.

We demonstrate a novel all-optical half-adder based on two semiconductor optical amplifiers (SOAs). Two optical bandpass filters are used to select the two idlers generated by four-wave mixing (FWM) effect of the first SOA. Therefore, the AND gate and XNOR logic are realized simultaneously. The second SOA acts as a NOT gate, in which the NOR logic is achieved with the input of the logic XNOR. As a result, the output is the sum of the two input bits and the carry. In the experiment, all-optical half-addition calculation is achieved between two 10 Gb/s signals.